US President George W. Bush has promised India full co-operation in developing its civilian nuclear power programme without demanding it sign a major nuclear arms control treaty.
A statement released after talks with Prime Minister Manmohan Singh said Mr Bush would ask Congress to change US law and work with allies to adjust international rules to allow nuclear trade with India.
Washington had barred providing atomic technology to India because of New Delhi's status as a nuclear power that has refused to sign the nuclear Nonproliferation Treaty, which was designed to halt the spread of nuclear weapons.
But the joint statement said: "As a responsible state with advanced nuclear technology, India should acquire the same benefits and advantages as other states."
India, which tested a nuclear weapon in 1998, agreed to identify and separate its civilian and military nuclear programmes, continue a moratorium on nuclear testing and place civilian nuclear facilities under the UN nuclear watchdog.
But these are all voluntary, not legal, commitments, and India remains outside the Nuclear Nonproliferation treaty.
Many are concerned about the expanding US co-operation with India, however, saying it sets a bad example for Iran, a Nonproliferation Treaty member, and North Korea, which the White House labelled members of an "axis of evil" along with pre-war Iraq.